Blends of thermoplastic resins and polyindene or coumarone-indene

ABSTRACT

Certain physical properties, such as heat-distortion temperature and flexural modulus, of certain commercially available thermoplastic resins are improved by blending with polyindene or coumarone-indene resins.

This is a continuation of U.S. Pat. application Ser. No. 909,323 filedon May 24, 1978, now U.S. Pat. No. 4,162,277, which in turn is acontinuation of Ser. No. 816,245 filed July 18, 1977, now U.S. Pat. No.4,117,040, which in turn is a continuation of Ser. No. 644,122 filedDec. 24, 1975, now U.S. Pat. No. 4,066,717.

The present invention relates to a method for improving physicalproperties of known commercially available thermoplastic syntheticresins by incorporating therein some polyindene and/or indene-coumaroneresin and to the resulting blends.

Coumarone-idene resins and polyindene are well known, relativelyinexpensive resins having been used for a variety of purposes in thepast including as fillers or extenders for rubber, and in asphalt tile.Coumarone-indene resins and polyindene are inexpensive by-products ofthe coal tar industry which are usually prepared by the acid catalyzedpolymerization of indene or coumarone-indene mixtures. Commerciallyavailable coumarone-indene copolymers are usually made from about 10% byweight of coumarone and about 90% by weight of indene, a mixture whichoccurs in coal tar residues.

We have discovered that some of the physical properties of certain wellknown commercially available thermoplastic resins, such as vinylchloride homopolymers and copolymers, polyolefins includingpolypropylene, polyethylene, polystyrenes, polyesters includingpolyethylene terephthalate, ABS, MBS, polycarbonates, and the like, aredramatically improved by blending some polyindene and/orcoumarone-indene resin with these materials.

In general, when from 1 to 50 parts, 5 to 30 parts preferred, by weightper hundred of resin (phr) of polyindene or coumarone-indene resin areblended with a resin of the aforementioned type, the physical propertiesincluding heat-distortion temperature, flexural modulus and otherproperties of the original resin are improved.

Thus, the blending of polyindene and/or coumarone-indene resins withcertain commercial thermoplastic resins will generally lower the cost ofthe blend, give better processability, give higher heat-distortiontemperature, give higher flexural modulus and in some cases give lowergas and vapor permeation rates to the blend.

According to the process of this invention, the blends of polyindene orcoumarone-indene resin and polystyrene, for instance, can be made in anyof a number of ways as by blending on a mill, in a banbury mixer orother type of internal mixer such as in a Brabender mixer.

In the following examples which further illustrate this invention, theamounts of the various materials listed are given in parts by weightunless otherwise specified.

EXAMPLE 1

A. Fifty parts of commercially available polyvinyl chloride were blendedin a Brabender internal mixer at 210° C. for 5 minutes with 7.5 parts ofa coumarone-indene resin (Cumar LX-509, Neville Chemical Company)(softening temperature of 120° C.). Test specimens were molded from theblend.

B. Test specimens were molded as in A above from polyvinyl chloride.

The test specimens from A and B above were tested for ASTM (D-646)heat-distortion temperature (HDT) and ASTM flexural modulus with thefollowing results:

    ______________________________________                                        Specimen   HDT(°C.)                                                                            Flexural Modulus (psi)                                ______________________________________                                        A          67           8.67 × 10.sup.5                                 B          58           4.02 × 10.sup.5                                 ______________________________________                                    

EXAMPLE 2

A. Fifty parts of commercially available polystyrene were blended in aBrabender internal mixer at 210° C. for 5 minutes with 7.5 parts ofcoumarone-indene resin. Test specimens were molded from the blend.

B. Fifty parts of polystyrene were blended in a Brabender internal mixerat 210° C. for 5 minutes with 7.5 parts of polyindene (prepared fromindene in toluene with BF₃ initiator, softening temperature of 240° C.).Test specimens were molded from the blend.

C. Test specimens were molded from polystyrene.

The test specimens from A, B and C of this example were tested for ASTMheat-distortion temperature (HDT) and ASTM flexural modulus with thefollowing results:

    ______________________________________                                        Specimen   HDT (°C.)                                                                           Flexural Modulus (psi)                                ______________________________________                                        A          79           2.99 × 10.sup.5                                 B          83           3.40 × 10.sup.5                                 C          77           2.54 × 10.sup.5                                 ______________________________________                                    

EXAMPLE 3

A. Fifty grams of commercially available polycarbonate were blended with7.5 grams of polyindene at 230° C. for 5 minutes in a Brabender internalmixer. Eight grams of this blend were compression molded at 215° C.(6000 psi) to give a 1/8-inch test bar.

B. A test bar of the polycarbonate alone was prepared as in A above forcomparison purposes. The following results were obtained:

    ______________________________________                                        Specimen   HDT (°C.)                                                                           Flexural Modulus (psi)                                ______________________________________                                        A          140          3.29 × 10.sup.5                                 B          136          3.15 × 10.sup.5                                 ______________________________________                                    

EXAMPLE 4

A. Fifty grams of commercially available polymethyl methacrylate wereblended with 7.5 grams of coumarone-indene copolymer in an internalmixer. Test bars of the blend were then molded.

B. Test bars of the polymethyl methacrylate used in A above wereprepared for comparison purposes. The following results were observed:

    ______________________________________                                        Specimen   HDT (°C.)                                                                           Flexural Modulus (psi)                                ______________________________________                                        A          91           4.63 × 10.sup.5                                 B          85           4.11 × 10.sup.5                                 ______________________________________                                    

EXAMPLE 5

A. Fifty grams of commercially available polyvinyl acetate were blendedwith 7.5 grams of coumarone-indene copolymer in an internal mixer. Testbars of the blend were then molded.

B. Test bars of the polyvinyl acetate used in A above were prepared forcomparison purposes. The following results were obtained:

    ______________________________________                                        Specimen   HDT (°C.)                                                                           Flexural Modulus (psi)                                ______________________________________                                        A          40           10.2 × 10.sup.5                                 B          <25          0.01 × 10.sup.5                                 ______________________________________                                    

We claim:
 1. A composition having improved properties comprising a blendof (A) 100 parts by weight of polyvinyl acetate and (B) from 1 to 50parts by weight of a member selected from the group consisting ofpolyindene an a coumarone-indene resin.